Thursday, September 06, 2007

In one area in our factory they want to buy ESD chairs so that they can eliminate their wrist straps.

Using ESD chairs is not a substitute for personal grounding through wrist straps. Personal grounding requires a reliable electrical connection between the body and ground, achieving a resistance less than 35 M ohm. Generally this cannot be achieved by a person sitting on a chair for two reasons. Firstly the resistance of the chair is usually too high, and secondly the contact between the body and chair cannot be guaranteed due to the clothing worn.

In my view the use of an ESD chair is to prevent the chair itself becoming a source of electrostatic fields which could cause ESD risks, and could increase the charging on personnel sitting on the chair. If you have chairs in your EPA they should be ESD chairs in any case.

About Me

Dr Jeremy Smallwood has been working as a static electricity consultant since 1987. He started his company Electrostatic Solutions Ltd to give top level static electricity research and development and consultancy services in 1997.